1. Field of the Invention
The present invention relates to a method for controlling a start/stop operation of an internal combustion engine in a motor vehicle, the controller activating a starting device which has a starter motor and a meshing device for the purpose of starting the internal combustion engine and of executing a start/stop operation, the rotational speed and position of a crankshaft of the internal combustion engine being detected with the aid of a detector device. The present invention furthermore relates to a computer program product and to a controller for a start/stop operation of the internal combustion engine in a motor vehicle, it being possible to start the internal combustion engine with the aid of an electric motor as the starter motor, and the controller having a microcomputer which includes a program memory for activating the starter motor which has a meshing device for meshing a starter pinion with the ring gear of an internal combustion engine.
2. Description of Related Art
To save fuel and lower emissions, methods are known for shutting down the internal combustion engine in a vehicle using an engine controller according to specified shutdown conditions, in particular after a specified timeout, for example at traffic lights or other traffic obstacles which force the vehicle to a temporary stop. An internal combustion engine is usually started with the aid of a starter pinion which may be activated by a starter motor which is meshed with a ring gear of an internal combustion engine. In such a design of the internal combustion engine, which is started with the aid of a starter pinion, minimum times which must pass before the internal combustion engine may be restarted exist for a restart.
A device and a method for operating a device having a starter pinion and a ring gear of an internal combustion engine are known from published German patent application document DE 10 2006 011 644 A1, the rotational speed of the ring gear and the starter pinion being ascertained for the purpose of meshing the starter pinion after shutting down the internal combustion engine at largely the same rotational speed as during coasting of the internal combustion engine. The starter pinion remains in a meshed state until the internal combustion engine starts to rotate.
Published German patent application document DE 10 2006 039 112 A1 describes a method for determining the rotational speed of the starter for an internal combustion engine of a motor vehicle. It further describes the fact that the starter motor includes a separate starter control unit for calculating the rotational speed of the starter and for first accelerating the starter pinion of the starter motor in a start/stop mode without meshing if self-starting of the internal combustion engine is no longer possible due to a lowered rotational speed. The starter pinion is introduced into the ring gear of the coasting internal combustion engine at a synchronous rotational speed.
Published European patent document EP 1 041 275 B1 describes a starting device for setting a ring gear of an internal combustion engine in motion with the aid of a starter pinion which may be activated with the aid of a starter motor. To avoid the danger of overloading the individual teeth of the starter pinion or the ring gear, which, act upon each other, the starter motor is first deactivated after meshing begins and is first driven under partial load and subsequently under full load after the starter motor has achieved a sufficient meshing depth.
An object of the present invention is to refine a method, a computer program product and a controller of the aforementioned type in such a way that vehicle comfort in start/stop mode is improved and the meshing of a starter pinion with a ring gear is achieved at a coasting rotational speed at reduced noise and wear.